After thrashing Bayern Munich 4-1 in their prior European outing, Hansi Flick's side followed that up with a seventh straight victory across all competitions.
Red Star Belgrade vs Barcelona Live Streaming UEFA Champions League: The Catalan club started life under Hansi Flick in sensational form, beating rivals Bayern Munich and Real Madrid last month.
Inter Milan won their first match of this season's revamped Champions League on Tuesday by sweeping aside Red Star Belgrade 4-0 at the San Siro
Serbia's champions Red Star Belgrade strongly condemned racist slogans chanted at Zlatan Ibrahimovic, during a Europa League match.
Liverpool were strong favourites away to Red Star in Serbia, but Jurgen Klopp's team were poor in a 2-0 defeat to the 1991 European Cup winners.
Mohamed Salah has scored 50 goals for Liverpool quicker than any other player in the club's history after just 65 appearances for the Reds.
French investigators are probing suspicions of match-fixing in Paris Saint-Germain's 6-1 win against Red Star Belgrade in the Champions League group stage.